This particular URL would show the attacker the configure.php file. There is no patch, that we know of yet, that prevents this attack. The best advice we’ve seen is to rename the admin folder something obscure so the hackers can’t just scan your site with this URL and find the file_manager.php file.

Other exploits we’ve seen use the same basic URL but the action variable is set as follows:

admin/file_manager.php/login.php?action=save

Then a URL to a remote site that stores a backdoor shell script. This backdoor then gets saved to the website. All a hacker has to do is to access the URL:

hxxp://[site]/osCSS/[name of shell script backdoor].php

and they have remote access to the site.

Again, if the admin folder is renamed to something obscure, this attack won’t work. This type of protection is aptly named, “security by obscurity” because all you’re doing is hiding the folder from the attacker, but until an official patch is released, this seems to be the best advice.

If you’ve been attacked by this and have some further information, please post a comment or email me at: traef@wewatchyourwebsite.com

If you need help in cleaning this up and checking for all backdoors on your site, please contact me directly at: traef@wewatchyourwebsite.com